I would like to have a delimiter whose upper half is the upper half of the delimiter [ and whose lower half is the lower half of the delimiter ( -- so that it be one continuous line, and also the matching delimiter whose upper half is the upper half of the delimiter ) and whose lower half is the lower half of the delimiter ] .
Correspondingly, I would like to have a binary (inequality) relation with the full-size sign > over the succession of a half-length = sign followed on the right by an empty space of the same horizontal extent as the half-length = sign, so that the the total horizontal extent of the combination of the the half-length = sign plus the empty space be the same as that of the full-size sign > . Such a binary relation could be called "greater than or half-equal to". Similarly, I would like to have a "less than or half-equal to" sign, which is a binary relation with the full-size sign < over a half-length = sign preceded on the left by an empty space of the same horizontal extent as the half-length = sign.
Can this be done without METAFONT (which I don't know at all)? Thank you very much for your help.